#include <fstream>
#include <iostream>

using namespace std;

char ch[100];
int main()
{
    int v[20], s=0;
    v[0] = 0;
    for(int i=1;i<=20;i++){
        int p=1;
        for(int j=0;j<i;j++){
            p=(p%10)*(i%10);
        }
        v[i]=p%10;
        s= s%10 + v[i]%10;
    }

    ifstream in("cifra.in");
    ofstream out("cifra.out");

    int t;
    in>>t;

    for(int i=0;i<t;i++){
        in>>ch;

        int len = 0;
        while(ch[len]!='\0')len++;
        //len++;

        cout<<ch[len-1]<<" /*/";

        int rez=0;
        if(len>3){
            rez = ((((ch[len-3]-'0')*10+(ch[len-2]-'0')*1)/2)%10)*s;
            for(int j=1;j<=((ch[len-2]-'0')*10+ch[len-1]-'0')%20;j++){
                rez+=v[j];
            }
            cout<<rez%10<<"\n";
        }
        else if(len==1){
            for(int j=0;j<=ch[len-1]-'0';j++){
                rez+=v[j];
            }
            cout<<rez%10<<"\n";
        }
        else {
            rez = ((((ch[len-2]-'0'))/2)%10)*s;
            for(int j=1;j<=((ch[len-2]-'0')*10+ch[len-1]-'0')%20;j++){
                rez+=v[j];
            }
            cout<<rez%10<<"\n";
        }
    }
    return 0;
}